College Lab Equipment Booking App with QR Check-in using Firebase

A lab equipment booking app replaces the paper register in most college laboratories. Today, a student reaches the lab to find the oscilloscope taken, two batches dispute the function generator booking, and the in-charge cannot trace who kept a multimeter past return time. The core problem is coordination without visibility: nobody sees free capacity beforehand, and nobody stays accountable after the slot ends.

This project builds that visibility as a working Android app. Students browse a catalog of lab instruments, reserve 1-hour slots across a 7-day window, and receive a QR booking pass encoding the reservation. Check-in and return are recorded by scanning the pass, every event timestamped and synced via Firebase. Because each booking is a transaction on its slot document, two students cannot claim the same equipment for the same hour. The in-charge dashboard turns the booking stream into live answers: what is free now, what is overdue, and which instruments carry the week's heaviest load.

The flow runs from catalog to dashboard without leaving the app. A signed-in student opens the equipment catalog, which shows each instrument with its bench location and free unit-slots for the day. Tapping an instrument opens the booking screen: a 7-day date strip and a grid of eight 1-hour slots, each showing remaining units. Confirming a slot runs a transaction that claims the slot document — the mechanism that makes double-booking impossible — and writes the booking record. The app then renders the QR booking pass, encoding booking reference, equipment ID, date, slot and student name. At the lab, the in-charge scans the pass: the payload is verified against the booking and check-in is timestamped. A return scan closes the loop and frees the unit. Every write lands in Firebase Realtime Database, so the dashboard's availability counts, overdue list and usage chart update on every connected screen within the design-target sync window.

1. The student signs in with email and password through Firebase Authentication; the UID tags every booking for accountability.
2. The catalog reads the equipment collection and shows free unit-slots per instrument for the selected day.
3. The booking screen offers the 7-day strip and the 1-hour slot grid; slots whose units are fully claimed render disabled.
4. Confirming runs a transaction on the slot document and writes the booking; the QR pass renders from the booking fields.
5. The in-charge scans the pass at the bench — the payload is verified, check-in is timestamped, and a second scan records the return.
6. The dashboard listens to the bookings collection and recomputes free units, overdue items and usage on every change.

Tech stack:

• Kotlin (Android)
• Firebase Authentication
• Firebase Realtime Database
• ZXing QR processing library
• Material Design 3
• Android Studio
• Gradle build system
• Git

The build centers on four capabilities that work together end to end. First, a slot-booking engine: students pick an instrument, a day from a 7-day strip, and one of eight 1-hour slots between 9 AM and 5 PM, with full slots visibly disabled before confirmation. Second, a QR booking pass: every confirmed reservation renders a scannable ISO/IEC 18004 code encoding the booking reference, equipment, date, slot and student — measured at approximately 88 ms from tap to visible pass in the demo build. Third, scan-based check-in and return: a scan at the bench timestamps arrival, a second scan records return, and the timeline on the pass updates itself. Fourth, the in-charge dashboard: live free-unit counts, a checked-out list, overdue returns with elapsed time, today's schedule and a 7-day usage chart, all recomputed from the realtime booking stream.

• [Slot-based reservation engine] Seven-day date strip with eight 1-hour slots per day from 9 AM to 5 PM, per-unit capacity counts on every slot, and fully-claimed slots disabled before the student can tap them.
• [QR booking pass] Each confirmed reservation renders an ISO/IEC 18004 QR code encoding the booking reference, equipment ID, date, slot and student name — approximately 88 ms from tap to visible pass, measured in the demo build.
• [Scan check-in and return] A bench-side scan verifies the pass payload against the booking record and timestamps arrival; a second scan records the return and frees the unit.
• [Double-booking-proof data model] A booking is a transaction on its slot document, not a blind insert — a second claim on the same slot fails and the app reports the slot as full.
• [In-charge live dashboard] Free units right now, the checked-out list, overdue returns with elapsed overdue time, today's full schedule and a 7-day usage chart, recomputed on every database change.
• [Overdue detection] Any checked-in booking past its slot end is flagged overdue automatically, with the elapsed time shown next to the student's name.
• [Firebase Authentication] Email and password sign-in; every booking carries the student's UID so each reservation is attributable.

Optional on request (not in the base build): push reminders before slots, kiosk self-check-in mode, fine calculation for late returns. Future scope: multi-department roles and approval workflows.

• Complete Android source code in Kotlin
• Firebase project setup guide (Authentication + Realtime Database)
• QR booking-pass module and bench-side scan flow
• In-charge dashboard with availability, overdue and usage views
• Working demo build for evaluation
• Project report PDF (10-section abstract included)
• Presentation slides for project review
• Viva Q&A document covering the data model, booking transaction and Firebase concepts